insulin, rate of metabolism, intelligence and behavior, and the ability to reproduce. >> so one of the biggest problems with bpa is it acts like this sex hormone, estrogen. and when you're exposed to extra amounts of this, it can cause all kinds of diseases. it happens to be a sex hormone that's used in products, which is, from the perspective of someone who cares about public health, just bizarre. >> still, representatives of the plastics industry and bpa producers continue to maintain it is safe at low doses. in march, the food and drug administration ruled that bpa is safe. it rejected a petition by the natural resources defense council to ban it, saying more studies were needed.